Fountain pen



H. H. ZODTNER FOUNTAIN PEN Oct. 31, 1950 2 Sheets-Sheet 1 Filed July 11, 1947 wo w Now hmm A IN VENTOR Harlan H. Zodfner ATTORNEYS Oct. 31, 1950 H. H. ZODTNER FOUNTAIN PEN 2 Sheets-Sheet 2 Filed July 11, 1947 IN VENTOR Harlan H Zodtner ATTORNE Y3 Patented Oct. 31,

UNITED STATES PATENT OFFICE 25281408 Harlan H. Zodtner, ,Janesville, Wis, assignor t'o The Parker Pen Company, alanes'vill, Wish-a corporation'of Wisconsin Application My 11', 1947','senai 1% 766369' i-rciaims. wilted-'56) My inventionrelates to fountain pens' and has to do particularly with a fountain pen of the type adapted to be filled by capillary action and embodying improved means for filling the ink reservoir and feeding ink from the reservoir to'the writing point.

One of the objects of this invention is to provide an improved fountain pen of the foregoing type.

Another object is to provide an improved capillary filIer-and-reservoir element of the type formed from a porous mass of material wherein the pores are interconnected and define a plurality of interconnected capillary ink storage spaces or cells. V

Another object is to provide an improved capillary filler element of the granular type wherein a plurality of interconnected capillary spaces'are defined by a mass of initially individualsolid particles.

Another object is to provide'a capillary filler element of the porous mass "type having improved means ior feeding ink from the capillary spacesto the writing element of a pen.

Still another object is to provide a capillary Still another object is to provide a capillary filler element of the porous mass type having improved filling and write-out characteristics.

A further object is to provide a capillary filler element of the porous mass type having improved air venting characteristics providing improved filling and writing-performance.

Other and more specific objects of the invention are to provide a capillary'fill'er element of the porous mass type having ink feedmeans incorporated therein for improving the feed of ink from the capillary ink storage 'spacesto the writing element; to provide acapillary filler element'of the porous mass type having interconnected capillary spaces or passages for feeding ink to the writing element which are of greater capillarity than the remaining capillary spaces" in the filler element thereby insuring that ink is always available at the writing point of the pen for instant writing; and to provideia capillary filler element of the porous mass type'which insures complete filling of the capillaryink Storage spaces when the end of the pen is inserted in a supply of ink. 1

f Other objects and advantages ofthei invention will appear from the following description taken in connection with .the appended :drawings, wherein:

Figure 1 is a longitudinal'sectional view taken through a fountain pen constructed inaccordqance with'the i'nvention'j "Fig'. 2' is a transverse sectional view taken along lined-'2 of Fig. 1;

Fig. 7 3 is a transverse --sectional "view takerr along line 3--3-of Fig. 1;

Fig. 4 is a transverse sectional view taken along line-44-of Fig. 1; r 1

Fig. 5 is-a -fragmentary,- longitudinaL-sectional view through the front end of another embodiment of the invention;

Fig. Bis atransverse sectional view taken along line 6"6 of Fig.*5

' Fig. 7 is a longitudinal sectional view of still another embodiment of the invention;

Fig.8 is a transverse-sectional view taken along line 8--'8 of Fig. 7

Fig. -9 is a transverse sectional view taken along the line 99 ofFigfl; J

Fig. 10 is atransverse sectional view taken along line ilk-.1 9 of Fig. 7 with a portion of the structure broken away;

Fig. 1 1 is a, per'spectiveview of the nib of the penishown in Fig. 7 and Fig. l2 isia longitudinal sectional view of a further embodiment of my invention.

The present invention is disclosed in connection with a pen of the desk type but isapplicable, with appropriate modifications. in structure details, .to pocket 'epens or pens which are convertible for use either as p'ocketzpens or desk ens.

Referring :now particularly to Fig. l of the drawings the fountain pen comprises apen body which includes .a forward body .member 2W or a: rear body member :or sectionZiil whicmisv suitablyrsecured to the forward. section asiby threads 202. The bodyirnembers" may :be formed of any suitable material such :as hard rubber or a suitable plastic. The front section 209 is formed with a hollow interior or bore 203 providing a reservoir section and. has a tapered forward portion 2% defining iafeed section which latter is substantially closed :at its forward end by an end wall "295 leaving only a small forward opening 206.

A writing element which may take the form of a nib 207 is secured-in the feed sectionand has its writing tip extending through the forward opening 2ll6'and exposedfor writing. -While the nib may 'takeany suitable form, I have found that a nib. of theconstruction shown in Fig. 11 is'particularly suitable, which nib includes a tapered ,generally conical body'f'wii having a tapered forward portion-formed with a pierce 2| l and .a slit 2l'2extendingfro1n the pierce 2!! to tion of the bodyrnember 2M as by a nib retainer which preferably takes the form-of .an externally threaded ring 209 screwed into threads 2H] formed in the body member '2 0 fl :and which ring to provide a plurality of passsages or cells of capillary sizes adapted to draw ink into the pen solely by capillary action during filling, retain ink therein against leakage when the pen is not in use and permit ink to be drawn to the nib by capillary action when the pen is used in writing. The capillary filler-and-reservoir element, also referred to as the capillary filler element, 2E5 preferably is formed of material which is capable of being wetted readily by the usual inks but which is relatively inert to such inks and will not react therewith to detrimentally affect either the ink or the capillary filler element. Among the materials which I have found suitable for this purpose are glass, hard rubber, metal such as silver, or plastics such as Lucite (methyl methacrylate resin) or Saran (vinylidene'chloride type).

A preferred method of forming the filler element is to provide a mass of initially individual separately formed solid particles or granules 2 it of suitable material and to dispose them in intimate contact with adjacent particles abutting. The particles 266 are of such size or sizes that the voids 2i? defined therebetween are of suitable capillary dimensions. Preferably the particles, or granules, or what for convenience may be termed beads are of spherical shape and thus mutually abut over relatively small areas of their respective surfaces and provide capillary spaces which are interconnected and in communication with each other thereby forming, in effect, a series of capillary passages extending longitudinally and transversely throughout the stacked mass of particles.

The beads 2H9 which lie in a zone extending longitudinally, preferably throughout the length of the filler element and preferably centrally thereof, and which form a core 2l8, are of smaller size than the remainder of the beads, that is, the beads in the portion of the filler element surrounding the core. Accordingly, the capillary spaces 226 in the core 2 I8 are of smaller size and greater capillarity than the spaces 2!! formed by the larger beads. The smaller capillary spaces 220 of the core are interconnected with each other throughout the core and provide a plurality of passages leading to the forward end of the pen. The spaces 220 are also interconnected peripherally of the core 2l8 with the adjacent spaces 2!? and thus serve'to connect the latter with the writing element as will hereinafter more fully appear.

The core 218 extends into the feed section of the body and to the writing element and is formed with a forward end portion 22| constituting, in effect, a feed element which is in contact with the underside of the nib adjacent the pierce 2H and slit 2E2 thereby providing capillary passages leading into ink feeding relation with the nib pierce and slit.

While the beads forming the capillary filler element may be inserted in the pen body loosely and thereafter compacted to form a mass in which all of the beads are in intimatecontact, as hereinafter explained more in detail, preferably the beads are formed into a unitary cellular structure in which each bead is attached to the abutting beads at the points of mutual contact. On the other hand, if desired, only the beads 4 forming the core may be joined into a unitary mass and the remaining larger beads may be packed around the core.

Where the beads are formed into a unitary cellular structure the latter may be suitably secured in the pen body by a ring 225 threaded into the forward body section 260 and against the rear end of the capillary filler element H5. The ring 225 may be provided with slots 226 in its rear face to permit insertion of a tool for screwing it into the body section 280.

The beads may be joined to form a unitary structure by arranging them in a stacked mass with adjacent beads in mutual abutment and then heating them just'sufiiciently to fuse them at their abutting surface portions to maintain them in fixed relation. The beads preferably are not heated enough to cause them to lose their spherical shapes or to increase the mutual area of contact more than is necessary merely to join them; thus no substantial change is made in the shape, size or arrangement of the voids. By way of example, in one particular case very satisfactory results were obtained by forming the beads of lime glass consisting of soda, lime and silica. The beads were thoroughly cleansed to remove all adherent foreign matter and placed in a heavy steel mold having a cavity of suitable shape and size to provide a mass approximately the size and shape of the desired capillary filler element. The mold was inserted in a furnace heated to an initial temperature of 1350 F. The beads were maintained in a nonoxidizing atmosphere by maintaining carbon dioxide in the interior of the oven surrounding the mold containing the beads. The heat supplied to the furnace was maintained but owing to the insertion of the mold, the temperature of the furnace cooled within three minutes to around 1240 F. After approximately four more minutes the temperature of the furnace again reached 1350 F. and this temperature was maintained for approximately five minutes more, after which the mold was removed from the furnace and allowed to cool in air. The resulting cell structure was firm and rigid with adjacent beads securely joined and with the void spaces between the beads approximately the same size and shape as in the initial stack of individual beads.

The reservoir chamber 293 is continuously vented to atmosphere in order to permit air to escape therefrom during filling, to equalize the air pressure exerted on the ink in the capillary filler element at all times, and to admit air to 3 replace ink which is Withdrawn from the pen in writing. Any suitable venting means may be em: ployed which provides relatively free communication between the interior of the pen body and the atmosphere. However, I prefer to use the arrangement shown in the illustrative embodiment wherein the vent is formed by a passage 22? in the rear body member 26! and a connecting passage or port 228 extending therefrom to adjacent the joint between the body members 280 and 20!. Preferably the joint adjacent the passage 228 is made sufficiently loose or free to permit air to pass therethrough. However, if desired, in order to permit a higher degree of venting where desired to speed up the filling operation, the .rear body member Zlll may be unscrewed slightly to fully expose the outlet end of the passage 228 .to atmosphere.

To fill the pen, the writing end of the pen is inserted in a supply of ink to place at least the nib slit in contact with the'ink. However, prefstably. the pen-is inserted into thes-ink: sufiiciently" toaplacethe forward end of; the-capillary. filler. element; ZI 5.;in:.direct contact-.with: the ink; Ink' isrdrawni by. capillary action into. theufillerx element 2'I5;and,rises.by capillarity along-the; walls.

of thexbeadszl I 9. and. of the beads 12 I 52; ink'; also may; rise along. capillary; spaces formed'rbetwe'en' the walls of the pen.bodyjandtheadjacent beads;

Air which is'in the empty or partially empty spaces or cells 225) and 2H; at thebeginning of the fillingoperation is forced therefromby; the incoming ink andpasses out of the fillerelement at the rear end thereof and through the vent passages 221 and228; Since-each1 space or cell is in communication with'a plurality of adjacent spaces the air can pass with relative :freedom rear- Wardly through the filleryelem'ent and little if any pressure is required to eject the air. Owing to the greater-capillarity of the 2smaller spaces 22!) in the core 2I8 as compared to the'spaces 2!! ink rises faster in the core and is drawn, from thence.v

into the spaces formedby the beads surrounding the core. However, owing to the large number of passages or channels along; which ink can rise in both the core and the surrounding portion of the capillary filler, element there islittle likelihood of air being trapped in the filler element but the air is entirely forced out of the filler element. If, for any reason, a small amount of air should be trapped in the filler element by the incoming ink thiswill not seriously impede the flow of inkupwardly Within the capillaryiillerv element especially since owing to the; greater capillarity of the core ink willrise in the ,core and will be drawn therefrom into the surrounding beads.

In writing, when thepointof thepen nib is placed in contact with a writing surface, the ink which is held in the; nib slit by capillarity is. brought into contact with the surface and the capillarity established between the surface and the nib is sufficient to overbalance the capillarity of the capillary fillerelement and ink is drawn therefrom and deposited on the writing surface. Ink drawn from. thenib slit is replaced by;-ink drawn into the nib slit from, the adjacent capillary spacesprovided by, the capillary filler element. Owing to the fact that the spaces 22!] of the core 2 I8 have greater capillarity than the spaces 2 I I of the surroundingportion of the capillary filler element, ink is drawn into the core and a continuous body or column of ink fills the spaces in the core andextends to the nib slit 2I2 so that ink is alwaysavailable at the nib slit. As ink is drawn from the pen and the spaces defined by the capillary filler element are emptied from the rear end toward the forward end the level of the ink will fall but the ink at all times during writing will tend to stand at a higher level in the core than in the remainder of the capillary filler element so that at no time will there beany break in the continuousbody or column of ink extending from the larger spaces 2 I Ito the nib slit 2 I 2 by way of the core 2 I8.

Air to replace ink withdrawn from the I capillary spaces or cells is drawn into the capillary filler. element through the vent passages above described and consequently the pressure of the air on the ink in-the capillary filler element is maintained at all times" substantially equal to a atmospheric pressure and there is no decrease inpressure within the-pen which might tend to retard the flow of ink during writing. Moreover the core, with its passages of greater capillaritylz sib'ility of 'tiiencreationiofi airfbubbles witliinztiie capillary fillenelement which might :tend to cause air; locking with the consequentretarding or: blocking: of the fiow of: ink toward theiwriting end.(of. :the:.pen.

The capillarity-of the cells in the capillary filler. element is suchthatinkistdrawn .into'the' capillary. filler. element duringzfilling: to suchi-a heightrastoo completely fill all. of the spaces-.-. The capillarity ofthese spaces is predetermined-19 by forming; the capillary. fillerelement of beads ofssuitablesizesl. In certain cases it ma berfoun'd.

sumcient. to: formrthe core entirely. of:.beads:of.

one particular size and .the remaining portiorrof.

thelcapillaryg filler of beadsxa-ll of anotherasizes- However, in .certainicases it maybe preferable-to provideycapillary spaces in the: portion of the:

filler relement most remote :from the writing; element-whichare of smaller size and greater cap?" illarity' thanqthespacesvnearer to the writing ele ment. In that eventthe beads-surrounding. the coreare formed in two? or more-longitudinally displaced layers, the beads' in successive layers being; ofv decreasing sizes in a direction away from'the writing element. This 1atter*c0nstruc-- tion is-:illustrated in Fig. 12 wherein thefi-ller' element 400 is formed as a porous masshaving.

a central core MN and a-surrounding portion 4- which-is-formed in several sections, such as the,

sections 402 and 403,- the-spaces in. each section being smallerand of greater capillarity than in the sections nearer to the writingelement 404;

In one practicalembodiment Of a fountain pen embodying ,my invention-and having overall ex-.;

terior dimensions .approximatelyequalto those: of'aconventi-ona1 fountain pen excellent results were obtained by employing a capillary filler element, the outer portion ofwhich was constituted,

by No. 4 beads having anaveragediameterof 0.6405 and .a core .formedtfrom No. 8. beads having an average diameter of. 0.020.! withfthe forward end. of the coreextending. across the entire front endof the interior of the pen body and into contact with the nibin amanner similar to that illustrated in Fig. 1 of the drawings. The} reservoir section was approximately indiameterand approximately, 1% in length fromth'e rearWardendof the.nib to the rear end of the.

reservoir section andthe feedlsection. was approximately, in length from the. rear. ends of the nib to the forward endof 'the pen body.

The core extendedthroughout the length-of'the capillary fillerelementand hadv a diameter of. approximately, &7.

It will bev understood that. where beads are: referred to herein as beingofthe same size they mayyaryslightly in size owing,to. manufacturing; variations. It. is desirable, however, that the: beads be as nearly uniform insize as practicable.

and it has been found that entirely satisfactory.

results'may be obtained with'beadswhich vary in sizeup to 10% in their diameter. However, the.

more nearly uniform the bead sizes the more accurately'the operational characteristics of the pen may be predetermined.

The capillarity of. the several capillary spaces. in the filler: element may be increased. by pro.- viding;'. wall. surfaces defining these passages which havea relatively high degree of wettabilit'ybythe inks with which the pen. is-used=v Thusthe, :height. of..rise of. the. ink and consequently the capacity of the reservoiras-wellras the: rate I of filling--may be substantially improved;

Satisfactory wettability of. the wall surfaces '0f..the beads-1 may ;be I obtained by forming-E thebeads, of materials which areinherently suitablyv wettable by the inks used, as, for example, the materials above specified. I have found that beads formed from glass have very desirable surface characteristics, although .beads formed of other materials such as Lucite, hard rubber, Saran and metal have been found satisfactory. The wettability of such surfaces may be increased in many cases by appropriate treatment depending upon the nature of the surface.

Where the beads are formed from glass very satisfactory increase in the wettability of the surface can be obtained by suitably etching the surfaces of the beads. In one specific example the beads which were formed of soft lime glass and had a diameter of approximately 0.040" were placed in a lead receptacle and a 60% solution of hydrofluoric acid was poured over the beads to fully immerse them. The beads were allowed to remain immersed for approximately 60 seconds and were removed from the acid and washed thoroughly'in water to remove all free acid. The etching reaction was allowed to proceed with the receptacle bein unheated except for the heat of reaction between the hydrofluoric acid and the glass forming the beads. Similar etching processes have been successfully carried out on other sizes of beads of soda glass in a manner similar to that above-described. However, where the beads are of smaller size than above stated the immersion time preferably is somewhat shorter.

Further increase in wettability of glass beads may be obtained by additionally treating beads etched in the manner above described. In one specific example beads etched as above described were immersed in a molten bath consisting of 95% chemically pure cuprous chloride and reagent grade of cupric sulphide maintained at a temperature of 1050 F. The beads were immersed for approximately 30 minutes and then were removed and allowed to cool in air, after which they were ready for assembly in a pen. In another specific example, etched beads were immersed for 30 minutes in a molten bath consisting of 90% silver nitrate and 10% sodium nitrate maintained at a temperature of'around 1050 F. Excellent results also have been obtained by subjecting unetched beads to one of the foregoing treatments in the manner described.

Wettability of the surface of the beads may also be increased by a somewhat different process. In one example of this process two drops of formaldehyde solution were added to ml. of silver nitrate solution and immediately thereafter the etched beads were inserted in the mixture and the mixture was swirled to thoroughly wet all surfaces of the beads. The contents of the dish were allowed to stand for five minutes and then 10 ml. of formaldehyde was added to the dish and contents thoroughly mixed. The beads were allowed to stand for ten minutes with occasional stirring of the mixture and the beads were then removed and thoroughly washed with distilled water. Thereafter the beads were dried in air at 250 F. and after cooling in air were ready for use. deposit permanently adhering to the beads.

A third method of improving the wettability V This process left a silvery perature of at least 250 F. under a pressure of pounds per square inch for six hours. The beads and the solution were thereafter removed from the autoclave and the beads removed from the solution and allowed to cool and dry in air. Variations of this process consisted in employing in lieu of sulphuric acid such materials as sodium carbonate or lithium chloride.

A somewhat different method of treating the beads has been found successful which method is suitable for treating not only glass beads but beads formed from hard rubber, metal such as silver, or a plastic such a methyl methacrylate resin. In one specific embodiment of this method a suitable granular abrasive material is ground to a powder which will pass a 1250 mesh screen and is thoroughly mixed with water. The water is then forced under pressures from 50 to 100 pounds per square inch through nozzles which atomize the water. The beads are placed at a distance of from 4 to 10 inches from the nozzles and the vapor containing the entrained abrasive is projected against the surfaces of the beads with sufficient force to roughen or pit the surfaces. The beads thus treated have surfaces formed with very minute depressions and valleys along which ink will rise rapidly to thoroughly wet the surfaces.

Instead of forming the beads from glass as above described, they may be formed from Lucite (methyl methacrylate resin) having incorporated therein, or treated after formation with, a material which increases the wettability of the surface of the beads. Excellent results have been obtained by mixing with the methyl methacrylate while the latter is in monomer form from 2 to 10% by weight, and preferably about 10% of Aerosol O. T. (di-octyl sodium sulphosuccinate) and thereafter polymerizing the methyl methacrylate.

The wettability of the surfaces of beads formed from Lucite (methyl methacrylate resin) may be increased by suitably treating the beads after formation. In one specific form of such treat- "mentthe beads were moistened with water and allowed to absorb water. Thereafter, silicon tetrachloride in the vapor phase was allowed to react, at room temperature and atmospheric pressure, with the absorbed water. The beads then were ready for use and were found to havesystem can be readily predetermined. Moreover.

such capillarities will remain substantially fixed during the life of the pen since the members defining the capillary passages are not subject to changes in shape, dimension or relative position during operation. The beads provide relatively smooth, substantiall nonabsorbent, wall urfaces defining capillary spaces of such size that ink is drawn therein during filling and held therein when the pen is not in use but which permit substantially all of the ink to be drawn therefrom by capillary action when the pen is used in writmg.

It will be understood that where spherical beads are employed in forming the filler element the spaces or voids therebetween may take any one of a number of shapes depending upon 7- the manner in which the beads surrounding such 11 If desired, after the larger beads have been inserted in the pen body, the tube 365 may be withdrawn. However, it may be left in the capillary filler element to serve as means for confining the beads forming the core and thus insure against intermingling of the small beads with the larger beads surrounding the core. Where the tube is left in the capillary filler element it is formed with a plurality of small perforations or openings 356 providing relatively free communication between the spaces defined by the larger beads and the spaces defined by the beads forming the core. In this case the tube 365 may if desired be formed from screen material of sufiiciently fine mesh to retain the small beads and yet sufficiently open to provide relatively free communication between the core and the surrounding portion of the capillary filler element.

The capillary filler element, and the tube where one is employed, are retained in the reservoir chamber 303 by the rear body member 30!, the inner end of which is adapted to abut the capillary filler element. Preferably, in order to prevent the smaller beads from entering the air vent passage 321, a retainer disc 36! as a thin walled disc having perforations 368 or as a screen is interposed between the rear end of the capillary filler element and the inner end of the rear body member 30 I.

It will be understood that in certain cases it may be found preferable to form the core as a unitary member in which the initially individual beads are integrally joined as above described and by disposing loose beads of larger size around the core to complete the capillary filler element. In

. this form of filler element it, of course, is not necessary to provide a central tube surrounding the core since the small beads forming the core are inherently retained in the desired position.

From the foregoing it will be seen that the present invention provides a capillary fountain pen having a capillary filler element of the granular type formed of initially individual particles which has improved filling and writing characteristics. Owing to the provision of the smaller capillary spaces in the core the feed of ink from the larger capillary spaces provided by the surrounding por tion of the core is insured and ink is maintained at all times at the nib so that the pen not only is in condition for instant writing but the ink is fed continuously and evenly when the pen is used in writing. Moreover, the provision of the core insures that a very high percentage of the ink drawn into the pen in filling may be withdrawn from the pen in writing thus providing a pen having a relatively high refill and write-out capacity.

The capillary filler element is extremely simple in form and can be assembled easily and inexpensively from readily obtainable and inexpensive materials. The capillary filler element is such that there are no critical adjustments necessary during assembly. Moreover, there are no elements which are subject to malfunctioning or which require any maintenance or adjustments during a long period of use of the pen. If for any reason the replacement of the capillary filler element should become necessary as for example such as might occur if the pen were abused, the capillary filler element can be readily removed and replaced at a relatively low cost and without operations requiring a high degree of skill.

I claim:

1. A fountain pen comprising a pen body having an ink reservoir section defining a reservoir chamber, a writing element at one end of said pen body, and a capillary filler-and-reservoir element in said chamber including a, porous mass defining a plurality of interconnected capillar spaces constituting the principal ink storage reservoir of said pen, the spaces in zone centrally of said mass and extending substantially throughout the length of said mass and to said writing element being of smaller size than the remaining spaces of said mass, thereby providing a series of capillary spaces of greater capillarity than the remainder of the spaces, communicating with the latter and in ink-feeding relation with said writing element.

2. A fountain pen comprising a pen body having an ink reservoir section defining a reservoir chamber, a writing element at on end of said pen body, and a capillary filler-and-reservoir element in said chamber including a mass of initially individual solid particles disposed in intimate contact in said reservoir section and integrally connected to one another at their abutting surface portions to define a unitary porous body having a plurality of interconnected capillary spaces extending throughout said body and constituting the principal ink storage reservoir of said. pen, the spaces in a zone extending longitudinally of said body and to said writing element being of smaller size than the remaining spaces to define capillary spaces of smaller size than the remainder of said spaces.

3. A fountain pen comprising a pen body having an ink reservoir section defining a reservoir chamber, a writing element at one end of said pen body, and a capillary filler-and-reservoir element in said chamber and defining the principal ink storage reservoir of said pen, said element including a first mass of solid particles of predetermined sizes disposed in intimate contact and defining therebetween a plurality of interconnected capillary spaces extending throughout said element, and a second mass of solid particles of smaller sizes than the particles in said first mass, disposed in intimate contact and extending longitudinally as a core throughout said first mass centrally thereof and to said writing element to define a plurality of capillary ink feed passages of greater capillarity than said capillary spaces and connecting those spaces which are adjacent said second mass in ink feeding relation to said writing element.

4. A fountain pen comprising a pen body having an ink reservoir section defining a reservoir chamber, a writing element at one end of said pen body, and a capillary filler-and-reservoir element in said chamber and defining the principal ink storage reservoir of said pen, said element including a first porous mass in said reservoir chamber and defining a plurality of interconnected capillary spaces, and a second porous mass extending longitudinally of said first mass and defining a plurality of capillary passages of smaller size and greater capillarity than said capillary spaces in said first mass for connecting said capillary spaces in ink feeding relation to said Writing element.

5. A fountain pen comprising a pen body having a reservoir section defining a reservoir chamber, a writing element at one end of said pen body, and a capillary filler-and-reservoir element in said chamber and defining the principal ink storage reservoirof said pen, said element including a core of cellular form extending from said writing element and substantially throughout the length of said reservoir section and having a plurality of interconnected capillary spaces therein, and a mass of solid particles surrounding and in intimate contact with said core and of such size as to define a plurality of interconnected capillary spaces of larger size than the spaces in said core with the spaces defined by said mass of particles communicating in ink feeding relation with the spaces in said core.

6. A fountain pen comprising a pen body having a reservoir section defining a reservoir chamber, a writing element at one end of said pen body, a capillary filler-and-reservoir element in said chamber and defining the principal ink storage reservoir of said pen, said element including a first mass of solid particles disposed in intimate contact in said reservoir section and having interconnected pores defining a plurality of interconnected capillary spaces therein, the particles in the portion of the mass farthest from said writing element being of smaller size than the particles nearer to said writing element and defining spaces of smaller size and greater capillarity, and a second porous mass extending throughout and surrounded by the particles of said first mass and having interconnected pores of smaller size than the smallest pores of said first mass and defining a plurality of capillary spaces connecting the spaces of said first mass to said Writing element.

7. A fountain pen comprising a pen body hav ing a reservoir section defining a reservoir chamber and a feed section, a writing element at one end of said pen body, a feed member in said feed section providing a capillary ink feed passage leading to said Writing element, and a capillary filler-and-reservoir element in said chamber including a porous mass having a plurality of interconnected pores and defining a plurality of interconnected capillary spaces constituting the principal ink storage of said pen, the spaces in a zone extending longitudinally of said mass and to said feed member being of smaller size and greater capillarity than the remainder of the spaces, thereby providing interconnected spaces of greater capillarity than the remainder of the spaces connecting the latter to said feed passage in said feed member.

8. A fountain pen comprising a pen body having an ink reservoir section defining a reservoir chamber, a Writing element at one end of said pen body, and capillary filler-and-reservoir means in said chamber defining the principal ink storage reservoir of said pen, said means including a first mass of solid, generally spherical particles,

the smallest of which are approximately 0.040"

in diameter disposed in intimate contact within said reservoir chamber and defining a. plurality of'capillary spaces and a second mass of solid, generally spherical particles approximately 0.020 in diameter disposed in intimat contact and eX- tending as a continuous core throughout a substantial portion of the length of said first mass and defining interconnected capillary spaces communicating with the spaces in said first mass for feeding ink by capillary action to said writing element.

9. A fountain pen comprising a pen body having a reservoir section defining a reservoir chamber, a writing element at one end of said pen body, a capillary filler-and-reservoir element in said chamber defining the principal ink storage reservoir of said pen, said element including a core of cellular form extending from said writing element and. substantially throughout the length of said reservoir section and having a plurality of interconnected capillary spaces therein, and a mass of solid particles surrounding and in intimate contact with said core and of such size as to define a plurality of interconnected capillary spaces of larger size than the spaces in said core with the spaces defined by said mass of particles communicating in ink feeding relation with the spaces in said core, and means for venting at least said larger spaces to atmosphere.

10. A fountain pen comprising a pen body having an ink reservoir section defining a reservoir chamber, a writing element at one end of said pen body, and a capillary filler-and-reservoir element in said chamber defining the principal ink storage reservoir of said pen, said element including a first porous mass having interconnected pores defining a plurality of interconnected capillary spaces, and a second porous mass having interconnected pores providing a plurality of capillary passages of smaller size and greater capillarity than said capillary spaces for connecting the capillary spaces in said first mass in ink feeding relation to said writing element, said second mass having a portion extending across substantially the entire end of said reservoir chamber adjacent said writing element and a portion extending longitudinally substantially throughout said first mass.

11. A fountain pen comprising a casing having a reservoir section defining a reservoir chamber, a Writing element at the forward end of said casing and a capillary filler-and-reservoir element in said chamber including a porous mass having interconnected pores providing a plurality of interconnected capillary ink storage spaces connected in ink-feeding relation to said writing element and constituting the principal ink storage reservoir of said pen, the capillary spaces in a continuous zone extending longitudinally throughout the major portion of the length of said filler-and-reservoir element being of smaller size and greater capillarity than the capillary spaces in other portions of said element whereby said smaller spaces draw ink by capillary action from said larger spaces as ink is withdrawn at said Writing element, in writing, and means venting said chamber to atmosphere, at least certain of said larger pores of said filler-and-reservoir being exposed to the air in said chamber whereby air under atmospheric pressure may enter said spaces to permit ink to be withdrawn therefrom, in Writing.

HARLAN H. ZODTNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 715,359 Dickie Dec. 9, 1902 1,001,225 Sinnott Aug. 22, 1911 2,187,528 Wing Jan. 16, 1940 2,311,488 Thomas Feb. 16, 1943 2,319,244 Lo Cascio May 18, 1943 2,342,904 Sledge Feb. 29, 1944 2,360,297 Wing Oct. 10, 1944 2,410,423 Brinson Nov. 5, 1946 2,421,079 Narcus May 27, 1947 

